In an atom why don’t the electrons float away ? The float around in the electron cloud but what keeps them from floating away ?

If an electron is in the electric field of a nucleus, the electron can occupy only certain energy levels. When it is sitting on one of these energy levels, it does not radiate, it does not loose energy.

Clouds are made of water droplets and ice crystals. A cloud's individual particles are so small, Also  that warm air rising from the earth's surface is able to keep them floating in the air.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.